Since Congress enacted welfare reform in 1996, thousands of single mothers have gone off welfare and found jobs, and child poverty rates have dropped slightly. Yet there is also evidence that the poorest families are now worse off as they have less income than when they were on welfare.

Such mixed results appear frequently in trying to understand the law's consequences, concludes Cornell researcher Rachel Dunifon in a review of more than 100 studies of welfare reform commissioned by the Pew Charitable Trusts' Economic Mobility Project.

Her analysis, "Welfare Reform and Intergenerational Mobility," is timely because this year Congress is expected to consider whether to reauthorize the legislation (formally known as Personal Responsibility and Work Opportunity Reconciliation Act) as well as the Temporary Assistance for Needy Families program. The law tied welfare to work requirements, placed time limits on public assistance and turned over benefits allocation to states.

"At the time it was signed into law, there were some predictions of dire consequences -- that the loss of the safety net would put many kids out on the streets or into orphanages," said Dunifon, associate professor of policy analysis and management in the College of Human Ecology. "Clearly that hasn't happened."

However, she noted, "some families are still falling through the cracks."

Another consequence of the law is that some teens have had to step in and care more for their younger siblings with more single moms working. Yet preschool-aged children tend to have greater stability, some studies suggest, from the overall net income gains by single-mother families.

A lack of data still persists, Dunifon said, on how the law has impacted such areas of child development as test scores, physical and mental health and economic mobility.

For instance, researchers suspect that because many poor single mothers work at low-wage jobs with unpredictable hours, long commutes and stressful working conditions, their parenting duties are strained. On the other hand, leaving welfare for employment may have boosted their sense of self-worth and made them more attractive marriage partners, leading to a rise in their economic standing.

Dunifon calls for qualitative studies that focus on the types of jobs held by poor working mothers and how they affect child care, parenting and mental health, noting the need for rigorous research that truly captures the effects of various welfare reform policies.

"The ideal study would be an experimental evaluation testing how various 'real world' approaches to welfare reform -- that is, those found in states today -- influence children and families," she writes. "Such research would have the strong benefits of a randomized experiment, combined with relevance to today's policy world."

Ted Boscia is assistant director of communications for the College of Human Ecology.